2026-05-28T22:56:34Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/399442026-02-03T11:28:50Zcom_10630_2254col_10630_37953

00925njm 22002777a 4500 dc Fernández-Plazaola, Unai author Cañete-Corripio, Francisco Javier author Martos-Naya, Eduardo author Díez-del-Río, Luis author 2025-07-31 In this work, we present a transmission system that uses single-carrier modulation M-ary symbols quadrature amplitude modulation (M-QAM) for underwater acoustic communications (UAC) in the ultrasonic band. It exploits the diversity that four hydrophones provide at reception in a single-input multiple-output (SIMO) 1×4 configuration and also includes, for each stream, a phase-locked loop (PLL) for synchronization and a turbo-equalization subsystem, with fractionally-spaced equalizer (FSE) and decision feedback equalizer (DFE) filters, adaptive by means of least mean squares (LMS) algorithm, both of which are driven by an low-density parity check (LDPC) decoder decisions. The paper describes the system design and analyze its performances on trials carried out on shallow waters of the Mediterranean sea. Achievable data rates exceeding 200 kb/s between links of transmission distances longer than 200 m are obtained with a satisfactory low bit-error rate (BER). U. Fernández-Plazaola, F. J. Cañete, E. Martos-Naya and L. Díez, "Design of SIMO M-QAM System for Ultrasonic Communications on Shallow Waters," in IEEE Open Journal of the Communications Society, vol. 6, pp. 6323-6335, 2025 https://hdl.handle.net/10630/39944 10.1109/OJCOMS.2025.3594489 Acústica submarina Ultrasonidos Comunicaciones digitales Design of SIMO M-QAM System for Ultrasonic Communications on Shallow Waters